SUPERQOT is an unholy concoction of the following bits and pieces:
QUAKE by id Software:
What you see is based on the original Quake (1996) by id Software - one of the most important games ever created. The version you're able to play here is a shareware / demo distribution you can still find on id Software FTP server: ftp://ftp.idsoftware.com/idstuff/quake/quake106.zip. It has its rendering engine replaced and a bit of scripting added to make you jump straight into the action, but otherwise - it's just good old Quake.
If you never played the original then go and download a modern version and start fragging! Hell, even if you did play the original you should still go and play it again. You'll find lots of info on the Interwebs about running Quake on modern Windows and other systems using various updated ports of the Quake Engine. This one is a good example http://quakeone.com/freequake/en.html.
DARKPLACES by LordHavoc:
The engine that this version is using is the magnificent DarkPlaces port created by LordHavoc. It's one of the most well built and maintained Quake Engine ports in existence. You can find the original source code and binaries here: https://icculus.org/twilight/darkplaces/. Great place to start modding and experimenting if you're into retro stuff.
WINEBOTTLER by Mike Kronenberg:
As a shortcut, SUPERQOT for Mac OS X is packaged as a Wine application using WineBottler. It allows the Windows version of SUPERQOT to run on OS X without the need to rebuild it on a Mac. Nifty stuff! For more information on WineBottler visit http://winebottler.kronenberg.org/
We modified the engine a wee bit to accommodate for the SUPERHOT mechanics and art style. If you'd like to get your hands on the source code modifications, please contact firstname.lastname@example.org for a copy.
Happy 1st of April! Stay awesome!
The SUPERHOT Team